离体正常乳腺组织350～850 nm波段光谱特性

采用带有积分球附件的紫外/可见/近红外分光光度计测量了离体正常乳腺组织在350～850 mn光谱范围的反射率和透射率,运用反向倍加法得到了离体正常乳腺组织在相应光谱范围的光学参数,分析了正常乳腺组织的光学穿透深度随波长的变化情况.实验结果表明:350～850 nm波段正常乳腺组织的约化散射系数μ'.大于吸收系数μa.μ's 随着波长的增加而减小,即从350 nm波长值为9.731 mm-1～850 nm波长值为1.476 mm-1.μa从350 nm波长值为0.798 mm-1～850 nm波长值为0.102 mm-1,410 nm波长处存在一个吸收峰,其值为0.506 mm-1.光学穿透深度随着波长的增加而增大,从350 nm波长值为0.199 mm-1～850 nm波长值为1.439 nm.基于反向倍加法计算获得乳腺组织的光学参数,采用Monte Carlo模拟得到其相应光谱范围的反射率和透射率,并与实际测量值进行比较,二者的一致性较好.实验结果为乳腺组织的光活检及其光学治疗提供重要参考.

Spectral Characteristics of Normal Breast Samples in the 350-850 nm Wavelength Range

Spectral characteristics of normal female breast samples in the 350-850 nm wavelength range were measured using a UV/Vis/NIR spectrophotometer system with integrating sphere attachment for measuring the diffuse reflectance and transmittance. The optical properties of normal breast tissue in vitro were obtained by the inverse adding doubling method. And then the optical penetration depths in this spectral range were analyzed based on the principle of tissue optics. The results show that the reduced scattering coefficient of normal female breast tissue is significantly higher than the absorption coefficient in the 350-850 nm wavelength range. The reduced scattering coefficient decreases with the wavelength increment. It reaches maximum at shorter wavelengths with a decrease at longer wavelengths and ranges from 9. 731 mm^-1 at 350 nm to 1. 476 mm^-1 at 850 nm. The absorption coefficient of normal breast tissue is about from 0. 798 mm^- 1 at 350 nm to 0. 102 mm^-1 at 850 nm. The maximal and minimal values are at 350 nm and 850 nm respectively. An absorption peak for the normal breast tissue is at 410 nm of wavelength with the value of 0. 506 mm^-1, which belongs to hemoglobin. The absorption coefficient remains relatively constant when the wavelength is longer than 600 nm. The optical penetration depth increases with the wavelength increment and ranges about from 0. 199 mm at 350 nm to 1. 439 mm at 850 nm. Deep penetration depth noted in normal breast samples, especially at longer wavelengths, reflects the weak absorption and reduced scattering at these wavelengths. The calculated optical parameters of normal breast samples by the inverse adding doubling method agree well with the Monte Carlo simulations. This study may be useful for breast optical biopsy or the optical diagnosis of breast diseases.